1. Field of the Invention
The present invention relates to an improved cooling structure for an electric vehicle for forcibly cooling batteries and electrical components of the electric vehicle.
2. Description of the Related Art
In general, an electric vehicle runs with electric energy stored in batteries. These batteries generate heat when they are charged and electricity is discharged therefrom (hereinafter, referred to as "when the vehicle runs"). To cope with this, batteries have to forcibly be cooled when they are charged and the vehicle runs, and as a technology of this type, the "Battery Ventilating Device for Electric Vehicle" is proposed in Japanese Patent Unexamined Publication No. HEI 10-121960. In this proposed device, an intake port and exhaust ports are provided in a battery box, and blower fans are mounted in the exhaust ports, whereby when operated, the blower fans take in outside air from the intake port and battery cells are forcibly cooled with air so taken in.
In general electric vehicles, an auxiliary battery is provided (for supplying electricity to various lamps fitted thereon), and therefore a system is adopted in such electric vehicles in which electricity is supplied from power batteries (battery cells 1) to that auxiliary battery via a downverter.
In addition, a battery charger should normally be equipped on the vehicle for supplying electricity from a commercial power source to the power batteries.
In other words, general electric vehicles are equipped with a downverter and a battery charger as well as power batteries, and the downverter and battery charger themselves also generate heat when in use.
FIGS. 13A, 13B show typical examples of conventional cooling structures for an electric vehicle.
In the example shown in FIG. 13A, an intake duct 102 is provided rightward of a battery box 101 and exhaust ducts 103, 103 are provided leftward of the same box 101. Blowers 104, 104 are disposed at respective predetermined positions along the exhaust ducts 103, 103. A downverter 105 and a battery charger 106 are disposed in the intake duct 102. The downverter 105 and the battery charger 106 are forcibly cooled with air taken from the outside, and thereafter batteries 107 . . . (hereinafter, the dots, . . . , means plurality) are cooled.
In the example shown in FIG. 13B, the intake duct 102 is provided rightward of the battery box 101 and the exhaust ducts 103, 103 are provided leftward of the same box 101. A forced draft fan 108, the downverter 105 and the battery charger 106 are disposed in the intake port 102. The downverter 105 and the battery charger 106 are first cooled with air forced in by the forced draft fan 108 and thereafter the batteries 107 . . . are cooled.
The example shown in FIG. 13A is characterized in that the necessity of blowers 104, 104 for exclusive use for the downverter 105 and the battery charger 106 can be excluded by forcibly cooling the downverter 105 and the battery charger 106 by the blowers 104, 104 for cooling the batteries 107 . . . However, this increases the overall length La of the battery box 101, and therefore the example is not suitable for a small electric vehicle.
Similarly, with the example shown in FIG. 13B, the overall length of the battery box 101 is increased, and therefore the example is also not suitable for a small electric vehicle.